The Lance Armstrong Foundation has formally dropped the name of the disgraced cyclist from its title following the biggest doping scandal in the sport's history.

The foundation has been informally known for years as Livestrong - the word adorning its well-known yellow wristbands. It will now formally be called the Livestrong Foundation, after officials filed paperwork with the Texas Secretary of State for a name change that became effective on Oct 30, spokeswoman Katherine McLane said.

"For most of its life, the organization has been known as the Livestrong Foundation, but making that change official is necessary and appropriate during a time of change for the organization," Ms McLane said.

Armstrong founded the charity in 1997, after he was diagnosed with testicular cancer and before he first won the Tour de France.

Since then, it has raised some $500 million and has evolved from a focus on testicular cancer research to addressing the needs of survivors of all cancers.

Armstrong, 41, announced on Oct 17 that he was stepping down as chairman but remaining on the board of the organization, which helps people and families affected by cancer.

That followed an Oct 10 report by the US Anti-Doping Agency (USADA) that said that the now-retired rider had been involved in the "most sophisticated, professionalized and successful doping program that sport has ever seen."

On Oct 22, Armstrong's seven Tour de France victories were nullified and he was banned from cycling for life.

Then on Monday, Livestrong chairman Jeff Garvey said that Armstrong had voluntarily resigned from the foundation "to spare the organization any negative effects as a result of controversy surrounding his cycling career."

He made the decision Nov 4, Ms McLane said.

"All of us - especially Lance - wanted Livestrong to have a presence that was bigger than its founder," board member Mark McKinnon said.

"We knew that in order to make the most profound and lasting impact for cancer survivors, the cause and the organization had to have its own persona. That's exactly what Livestrong has become and Lance helped shape that effort."

Armstrong declined through a manager to comment. He said at the foundation's gala last month that the organization's mission is bigger than him. "We will not be deterred; we will move forward," Armstrong said that night.